Max is NOW!

In an effort to expand my own knowledge and the knowledge of my readers, I thought a nice, elementary level piece of science might go well today.

What is Fog?

Although I don’t remember learning this specifically, I was pretty sure it was just a cloud that’s on the ground. And I was right. Of course the science of fog and clouds in a bit more technical. But here’s what wikipedia (as well as the other science sites it stole from) has to say about it:

Fog is a cloud that is in contact with the ground. Fog is usually the only clouds that touch the ground and it only differs from other clouds in that it touches the surface of the Earth. The same cloud that is not fog on lower ground may be fog where it contacts higher ground such as hilltops or mountain ridges. Fog is distinct from mist only in its density. Fog is defined as cloud which reduces visibility to less than 1 km, whereas mist is that which reduces visibility to less than 2 km. (http://en.wikipedia.org/wiki/Fog)

Given that my scientific inquiry was based on the nice “fog” this morning in the Portland downtown area, and that apparently the “fog” was actually a mist, I guess that the article should have been named “What is mist?”

All that aside, the science of fog/mist/clouds is rather interesting. It has to do with the density of water vapour in the air, and whether that density can be sustained in vapour or if it becomes too dense and the water starts collecting around particles of dust and the like.

I found a fun site for more info, including the technicals - http://library.thinkquest.org/C003603/english/fogandmist/whatisfog.shtml

Enjoy your science.

Photos from downtown Portland area this morning (11/17/2008):